Mirtazapine is a commonly prescribed medicine in the UK, used for depression & anxiety. If you have just been prescribed mirtazapine, this page explains what it is, the brands and strengths it comes in, how to take it, and how to have it dispensed and delivered free on the NHS with PillSorted.
This content has been medically reviewed and approved by Zeinab Ardeshir (GPhC 2075730), Superintendent Pharmacist at PillSorted (GPhC-registered online pharmacy 9011258). Last reviewed: 2 July 2026.
What is mirtazapine?
Mirtazapine is an antidepressant used mainly for depression. It is often taken at night because it can make you feel sleepy.
Brands and strengths
Mirtazapine is the name of the active ingredient. In the UK it is sold as generic mirtazapine and under the brand name Zispin — both contain the same active ingredient and work the same way. Common strengths:
- Mirtazapine 15 mg tablets
- Mirtazapine 30 mg tablets
- Mirtazapine 45 mg tablets
- UK brand: Zispin
What mirtazapine is used for
- Depression
How to take mirtazapine
Usually taken once a day at bedtime, with or without food. It can cause drowsiness and increased appetite. Do not stop suddenly without advice. Always follow your prescriber’s instructions (BNF).
Side effects
Common effects include drowsiness, increased appetite and weight gain, and dry mouth. Seek urgent help if your mood worsens or you have thoughts of self-harm. This is not a full list — see the patient information leaflet (BNF).
Mirtazapine: frequently asked questions
Yes. Zispin is the original brand name for mirtazapine; the generic is the same active ingredient.
It commonly causes drowsiness, so taking it at bedtime can help with sleep and reduce daytime sleepiness.
Yes. If you have an NHS prescription for mirtazapine, you can nominate PillSorted as your NHS pharmacy and we will dispense and deliver it to your door for free.
Get your mirtazapine delivered free on the NHS
If you have an NHS prescription for mirtazapine, PillSorted dispenses and delivers it to your door — completely free. Nominate PillSorted as your NHS pharmacy once, and we take care of your repeat prescriptions from then on.
What you get
- Free delivery, every time — your medicine posted to your door, always free.
- Your whole family, one account — manage everyone’s prescriptions in one place.
- Real pharmacists, every prescription — every order checked by our UK pharmacist team.
How it works
- Choose PillSorted as your NHS pharmacy
- We collect your prescription from your GP
- Your medication is delivered free to your door
Sources: NICE; BNF — Mirtazapine.
This page is for general information only and is not a substitute for advice from your GP or pharmacist. Always take your medicine exactly as prescribed. For advice about your own health, consult a clinician.